Grease thickened with coated fibrous asbestos

ABSTRACT

1. A GREASE COMPOSITION HAVING SUPERIOR SHEAR STABILITY, WATER-RESISTANCE AND EXTREME PRESSURE PROPERTIES, COMPRISING FROM ABOUT 65 TO 90 WEIGHT PERCENT OF LUBRICATING MINERAL IOL FROM ABOUT 35 TO 10 WEIGHT PERCENT OF A THICKENING SYSTEM MADE UP OF 25 TO 9 WEIGHT PERCENT OF FIBROUS ASBESTOS AND ABOUT 10 TO 1 WEIGHT PERCENT OF POLYMERIC COATIG AGENT HAVING RECURRING UNITS INCLUDED WITHIN THE STRUCTURES:   (1,2,2,3,4-PENTA(R)-1,2-DIHYDRO-QUINOLINYL-R)N   WHEREIN THE AVERAGE DEGREE OF POLYMERIZATION RANGES FROM 2 TO ABOUT 10, AND R IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL RADICALS AND HYDROXYLATD ALKYL RADICALS, SAID ALKYL RADICALS CONTAINING FROM 1 TO 6 CARBON ATOMS.

I Cl. 252-13 3,846,312 THICKENED COATED GREASE FIBROUS ASBESTOS EdwardA. Cross, Houston, Tex., and Richard L. Frye,

Baton Rouge, La., assignors to Texaco Inc, New York,

No brawing. Continuation-in-part of application Ser. No.

v, 740,084, June 26, 1968. This application Apr. 30, 1970,

Ser. No. 33,534

' Int. Cl. C10m 5/02, 5/20 7 Claims ABSTRACT OF THE DISCLOSURE Thisinvention concerns shear stable water-resistant,

high dropping point greases having improved E.P. properties comprising amajor amount of a lubricating oil thickened with a minor amount offibrous asbestos coated with at least one polymeric quinoline coatingagent.

This invention is a continuation-in-part of Ser. No.

740,084 filed June 26, 1968, now issued as US. Pat.

3,520,807. Thisinvention is related to grease compositions thickenedwith fibrous inorganic materials coated with hydrophobic materials.

More particularly, this invention concerns lubricating 'oils thickenedto greast consistency with inorganic fibres coated with at least onepolymeric quinoline coating agent. The use of finely divided fibrousmaterials such as asbestos or fibrous glass as a filler or thickener inlubri- "cating greases is old in the art. See for example Manufactureand Application of Lubricating Greases, by C. J. Boner, 1954 edition,pages 757-794, particularly pages 771-773, Lubricating Greases: TheirManufacture and Use, Klembard, published by Reinhold Publishing Co.,

pages 725, 756, as Well as pages 71, 311, etc. In addition, the subjectis also extensively covered in the patent literature, see for exampleUS. 3,010,896 (Odell) and US. 3,424,678 and US. 3,433,743 (Morway etal.). Unfortuto by Boner have poor shear stability and have relativelypoor stability in the presence of water. The greases disclosed by Odellcomprise water soluble surfactants which must be applied in an aqueousmedia and require separate and lengthy drying and extraction steps tosubstantially remove the unwanted water in the system. Further, the

resultant greases, while relatively satisfactory, are not i superiorgreases. The two Morway, et al. patents require the use of a particularcolloidal size asbestos substrate to I be'elfective.

Recently the applicants have discovered that greases thickened withinorganic fibrous substrates coated with cersitu or preformed and thusobviate tedious and costly dehydration steps in grease manufacture.

In view of the above-recited shortcomings of the prior "art, theapplicants thickening systems and the greases pro- "duced fro'm thesesystems represent an advance in the art . I Itisan object of thisinvention, among others, to provide novel greases having good shearstability, water resistance and ER properties.

United States l atent C 'nately, these greases have been less thansatisfactory in one or more respects. For example, the greases alluded3,846,312 Patented Nov. 5, 1 974 ice It is another object of thisinvention, among others, to provide novel thickening systems applicableto both synthetic and natural oils of lubricating viscosity.

A more specific object of this invention is to provide novel coatingagents which can be applied to both colloidal and non-colloidal asbestossubstrates in a non-aqueous environment.

Additional objects will suggest themselves to those skilled in the artafter reading this disclosure.

In practice, a grease is prepared by admixing a major amount of one ormore oils of lubricating viscosity and a minor amount of optionaladjuvants, with a thickening system comprising (a) at least oneinorganic fibrous material, and

(b) at least one polymeric quinoline coating agent, under reactionconditions of time and temperature suitable to produce a coating of saidpolymeric quinoline coating agent upon said inorganic fibrous materialuntil a lubricant of grease-like consistency is obtained. If desired,the grease can be subsequently milled to a harder consistency.

In the favored practice, a grease comprising about 55 to 97 weightpercent of a mineral oil of lubricating viscosity and and about 45 to 3weight percent with a thickening system containing inorganic fibrousmaterial and at least one polymeric quinoline is prepared by admixingsaid grease components at temperatures ranging between about 200 and 450F. until the desired thickening takes place.

In the most favored practice, a grease having superior shear stability,water-resistance and extreme pressure properties is prepared by admixingat between about 200 and 450 F. about 65 to 90 weight percent of amineral oil of the naphthenic of parafiinic type with about 25 to 9weight percent of fibrous asbestos and about 10 to 1 weight percent ofsaid polymeric quinoline coating agent.

In the preferred practice, a grease product having superior propertiesof shear stability, water-resistance and extreme pressure properties isprepared by admixing between about 325 F. and 450 F. the followingcomponents:

about to weight percent of a parafiinic oil having initial viscositiesbetween about 800 SUS to 2000 SUS and about 15 to 9 weight percent ofchrysotile asbestos coated with about 5 to 1 weight percent of at leastone trimethyldihydroquinoline type polymer having the polymeric unitdefined infra.

In order to supplement the subject disclosure of this invention, thefollowing additional disclosure is described more fully below:

A. Fibrous Inorganic MaterialsThe fibrous materials which are suitableas substrates for the novel coating agents of this invention include awide variety of naturally occurring materials which are found or can bemade in the finely divided state and which, under the conditions offormulation, manufacture or application of the grease, are stable tochemical and thermal attack. Most of the materials will range in lengthfrom a few millimicrons to tens of thousands of millimicrons, or willrange in diameter from fractions of a micron up to about 500 or moremicrons. More commonly, the lengths will range from about 500millimicrons to 50,000 millimicrons.

A useful group of fibrous inorganic materials which are employed assubstrates are the siliceous and carbonaceous materials having therequisite stability and size require ments referred to above. Theseuseful favored materials are the various mixtures of alkaline earthmetal silicates with other metal and metal oxides, as Well as fibrousglass, fibrous carbon and fibrous graphite.

The favored fibrous materials are the naturally derived silicatemixtures generically referred to as asbestos. They can be of the longfibered or short fibered type, colloidal or non-colloidal. Asbestos isfavored as a class since it is a plentiful, inexpensive material whichis relatively stable to chemical and thermal attack which, when coatedwith the novel coating agents of this invention, are superior thickeningagents for converting lubricating oils to greases. The most commonlyknown types of fibrous asbestos and their theoretical formulae appearbelow:

Type of Asbestos:

Actinolite Ca(Mg.Fe) (SiO H O Amosite (Fe.Mg)SiO 1-5% H O Anthophyllite(Mg.Fe) Si O (OH) Chrysotile 3 MgO.2SiO 2H O Crocidolite NaFe (SiO FeSiOH O Tremolite Ca Mg Si O OH) 2 The information on asbestos presentedabove, as well as any other data or description relating to asbestos,unless noted otherwise, is taken from the article by M. S. Badolletentitled Asbestos, A Mineral of Unparalleled Properties, which appearedin Transactions of the Canadian Institute of Mining and Metallurgy, Vol.LIV 1951, pages 151-160. As is well documented in the literature,conventional forms of asbestos, particularly asbestos floats, amongother forms of asbestos, may be used in greases as long as the particlesize falls within the usual size limitations of asbestos fillers. Thatis, the asbestos may range in length from a few millimicrons tothousands of millimicrons. Similarly, diameters may range from less thana millimicron up to 100 millimicrons or more with a more useful range ofdiameters being within 10 to 75 millimicrons. While asbestos substratesare favored as a class, as is frequently the case, where the classcomprises a large group of entities, some members of the class are moredesirable or superior for one reason or another than the rest of theclass as a whole, and are therefore preferred. In this instance, thechrysotile form of asbestos is preferred because it is available in anespecially high state of purity, substantially free from physical andchemical contaminants, and most important, because when coated with thecoating agents of this invention, thicken oils of lubricating viscosityto produce greases having superior properties. Unless otherwise noted,when chrysotile asbestos fibers are referred to in the examples it willfall within the range of properties shown below:

Brightness (GE) 70-80 Refractive Index 1.40-1.60 Dispersion in waterCompletely at pH ranges of about 4-6 Surface Area 14-16 sq. meters/ gramOil Absorption 14-16 cc./1O grams of fibers Water Retention -25 gramsper gram of water Dry Bulk Density Fiber Dimensions: 2-2.5 lbs/cu. ft.

O.D. 20-30 millimicrons I.D. 6.0 millimicrons Length 2000-30,000millimicrons.

B. Lubricating OilsThe lubricating oils employed as the base fluid inthis invention may be natural (mineral) synthetic or blends of theseoils. The mineral oils used are those of the paraffinic, naphthenic,asphaltic or paraffinicasphaltic type derived from crude oils byrefining procedures including distillation, cracking or polymerization.These oils, like their synthetic counterparts, to be described morefully below, will have Saybolt Universal Viscosities in the range fromabout 75 seconds at 100 F. to about 225 seconds at 210 F.

The synthetic oils will include those of the ester type, the ether typeand silicones in the monomeric or polymeric form. The ester type oilsare derived from esterifying al cohols, particularly aliphatic alcohols,diols, polyols and the like with organic acids particularly aliphaticmonoand/or dicarboxylic acids. The aliphatic acids ordinarily containfrom 3 to 25 carbon atoms and the alcohol, coreactant ordinarily hasfrom 2 to 20 carbon atoms. Illustrative esters are as follows:diisooctyl azelate, di-Z-ethylhexyl sebacate, di-Z-ethylhexyl adipate,di-2-ethylhexyl azelate, dilauryl azelate, di-sec-amyl sebacate,di-2-(2- butoxyethoxy) ethyl alkenyl succinate, the di-n-deconate of1,4-butanediol, the dilaurate of 1,4-hexanediol, the dioctanoate of1,5-pentanediol, the dilaurate of tetraethylene glycol, the trimethylpropane triheptanoate, the diocetenoate of 1,5-pentanediol and the like.

The lubricating base oils preferred for thickening are mineral oilsselected from the group consisting of naphthenic oils having viscositiesat F. ranging from about 800 SUS to 2000 SUS and higher. These oils maybe derived from blends of oils having lower and higher viscosities. Theabove oils are preferred as bases for greases, particularly under highpressure conditions because they produce greases particularly resistantto bleeding or separation.

C. Optional AdjuvantsThe term adjuvant as used throughout thisdisclosure is used to describe all the materials added to a lubricant toimpart or enhance desirable properties or to eliminate or minimizedeleterious properties. These materials can be of diverse chemicalstructure and include oxidation inhibitors, E.P. agents, wear preventionagents, stringiness inhibitors, dropping point improvers and tackinessagents. Illustrative adjuvants are metal oxides, phenyl naphthylamines,mercaptobenzothiazoles, dibenzylsulfides, tricresyl phosphates,chlorinated waxes, fatty soaps, polyalkylene polymers. When adjuvantsare employed they seldom total more than 10% by weight of the finishedgrease and are added at the expense of the lubricating oil component.

D. Polymeric Quinoline Coating AgentsThis is the generic term used todescribe the oil-soluble or oil-dispersible polymers having recurringunits included within the structure:

wherein n which represents the average degree of polymerization is from2 to about 20, R is selected from the group consisting of hydrogen,alkyl radicals and hydroxylated alkyl radicals, said alkyl radicalspreferably containing from 1 to 6 carbon atoms.

The above polymers are known materials whose preparation and propertiesare disclosed in the technical and patent literature. These polymers canbe produced among other methods by polymerization monomers obtained fromthe quinoline synthesis which comprises reacting aromatic primary aminessuch as toluidine or aniline with a carbonyl compound such as acetone ormethyl ethyl ketone. For example, the reaction product of aniline andacetone yields 2,2,4-trirnethyl-1,2-dihydroquinoline and the reaction ofaniline and methyl ethyl ketone produces 2methyl-2,4-diethyl-1,2-dihydroquinoline. Other monomers are2,2,4,8-tetramethyl-1,2-dihydroquinoline, 2,2,4,7-tetramethyl-1,2-dihydroquinoline, 2,8dimethyl-2,4-diethyl-1,2-dihydroquinoline, 2,7 dimethyl-2,4-diethyl-2,4-diethyl-1,2-dihydroquinoline and 2,6dimethyl-2,4'-diethyl-l,2-dihydroquinoline among others. I

The polymerization is carried out by heating monomers of the typedescribed above at moderately elevated temperatures in the presence of adilute acid. The polymerized materials are also available from acommercial process which comprises heating the monomers between aboutll0-l50 C. in the presence of dilute aqueoushydrochloric acid for atleast 16 hours.

While generally the above-described class of polymeric materials aresuitable coating agents, as is frequently the case in a large group orclass, some members of the group are favored for various reasons to thegroup or class as a whole. In this instance the favored polymericcoating agents are included within the structure:

wherein n, which again represents the average degree of polymerization,ranges from about 3 to 6.

The preferred polymeric quinoline coating agents is a commerciallyavailable polymer of 2,2,4-trimethyl-1,2-dihydroquinoline obtained fromB. F. Goodrich Co. or the Vanderbilt Corporation, consisting chiefly ofthe trimer, referred to as TMHQ.

E. Processes for Preparing the Inventive Thickening Systems-Twoprocesses are illustrated:

1. In situ 2. Preforming (1) In situAt least two variations are possiblein regard to when the coating agent is added. In the first procedure thecoating agent is added with the initial charge, while in the secondprocedure the coating agent is added on the cooling cycle. The followingare illustrative of the variations when asbestos, the preferred fibroussubstrate is employed.

' In the first procedure, the kettle, fitted with heating and agitationmeans, is charged with lubricating oil, asbestos and the coating agent,and the mixture is vigourously agitated while heating between about 200to about 400 F. to thoroughly disperse the ingredients. After a heatingperiod of about 30 to 60 minutes the batch is cooled to about 200 to 325F. by removing the heat source and/ or quenching by the addition oflubricating oil. After holding at the reduced temperature for about 30to 60 minutes, the thickened material is milled through a device such asa colloid mill to the desired consistency.

In the second procedure, the grease kettle is charged with lubricatingoil and fibrous substrate and heated between about 200 F. to about 450F. After heating 30 minutes to 60 minutes, the charge is cooled tobetween about 200 to 325 F. either by removing the heat source or byquenching the charge with a minor to a major portion of additionallubricating oil. At this time the coating agent is added and the chargeis held for about 30 minutes at this temperature and brought to thedesired consistency by milling.

(2) PreformingIn this procedure a coated fibrous substrate such asasbestos, previously prepared by either of the two variations describedabove, is admixed with lubricating oil to be thickened and is heated toabout 340 to 405 F. for a period ranging from 5 to 60 minutes. At theend of this time the charge is cooled and brought to the desiredconsistency.

The in situ process for preparing the greases is preferred inasmuch asit requires less handling and shorter process cycles.

F. Preferred Grease Composition-The preferred greases comprise:

(a) from about 80 to 90 parts by weight of a mineral oil. having -SUSviscosities at 100 F. ranging from about 800 to 2000 SUS,

(b) from about to 9 parts of colloidal chrysotile asbestos and (c) fromabout 5 to about 1 parts by weight of at least I CH wherein n=3.

G. Ratio of Thickening System to Grease and Ratio of Fibrous InorganicMaterial to Coating Agent Required- The amount of thickening systemrequired is a variable dependent upon a number of factors, primarily thefibrous material and the coating agent employed.

Thickening effects are obtained when the amount of thickening systempresent comprises from about 1 to 30 parts by weight per parts by weightof final grease product. However, erratic and marginal results areobtained when either of the two extremes of concentration are employed.On the other hand, consistently good results are obtained within asomewhat more restricted range of about 20 to 10 parts by weight ofthickening system per hundred parts by weight of grease, and thisrepresents the preferred range. The ratio of fibrous inorganic materialto coating agent is a variable dependent upon the fibrous substrate andcoating agent employed. Ordinarily the fibrous inorganic material shouldbe present in reasonable excess over the coating agent, that is varyingfrom 1.25:1 to 15:1. When asbestos is the substrate to be coated,favorable results have been obtained when weight ratio of asbestos tothe coating material varies between 1.5 :1 to 10:1. Inasmuch as the bestresults have been found in ratios ranging from 2:1 to 7:1, this weightratio range is preferred.

H. Ratio of Lubricating Oil to Coated Substrate- Generally this ratio isnot especially critical. However, favorable results have been obtainedwhen the lubricating oil to coated substrate is between 3:1 to 15:1.When the favored substrate asbestos is used, the preferred weight gatioof lubricant to coated substrate varies from 4:1 to

In order to describe the inventive concept in the greatest detail, thefollowing illustrative examples are submitted. 'Unless otherwiseindicated, all parts and percentages are by weight rather than volume.

EXAMPLE l.MINERAL OIL THICKENED UNCOATED ASBESTOS An appropriately sizedreaction vessel equippedlwith heating, cooling and stirring means ischarged with 13.8- parts by weight of the colloidal chrysotile asbestosdescribed on page 6 and 63.1 parts by weight of mineral oil 1 and heatedwith stirring to 400 F. The heat is turned off and an additional 20parts by weight of the mineral oil is added to the stirred reactionvessel to quench-cool to 200 F. At this time the grease is milled toconsistency using a colloid mill having a 0.003 inch clearance. As TableI indicates, the resultant grease has unsatisfactory shear stability andwater sensitivity properties.

EXAMPLE 2.PREPARATION OF A GREASE THICKENED WITH TMHQ POLYMER A 96.9parts by weight portion of the uncoated asbestos thickened grease ofExample 1 is charged to a reaction vessel as previously described in thepreceding example and heated with stirring at 250 F. Then 3.0 parts byweight of the preferred TMHQ polymer wherein n=3 is added and themixture is stirred for 30 minutes. As the data in Table I shows, theresultant grease is satisfactory A refined parafiinic oil having aviscosity of 1600 SU at 100 F.. 117.8 at 210 F. and a flash point of 560F. s

EXAMPLE 3.PREPARATION OF A LUBRICATING GREASE THICKENED WITH ASBESTOSCOATED In all three instances satisfactory greases are produced.

EXAMPLES 8 AND 9.-GREASES PREPARED USING OTHER INORGANIC FIBROUS SUB- HTMHQ POLYMER STRATES COATED WITH TMHQ In this example, the TMHQ coatingagent is added dur- Example; Inorganic fibrous materials charged 10.8parts by weight of the mineral oil and 2.25 2: $2 33 $262 25; asbestosdescnbed parts by weight of the asbestos components used in Exi ig h f63? compolcllems l g g 11 (1 In both instances satisfactory greases areobtained.

t ere 0r 3 mmute? an quenc. e Yt As the specification, including theexamples indicate, tron of 1.5 parts by welght of additional numeral 011at h a t e novel greases are advantageous 1n several respects 30o Atthis time parts by Welght of the TMHQ 5 particularly when asbestos isutilized as the fibrous incoating agent of Example 2 is added and thebatch is held 6r anic material to be oat d F 1 at 300 F. for anadditional 30 minutes. Finally an addig f t E e or greases tional 1 partby weight of the mineral oil of Example 1 is i 8a ac cry to exce emwaterireslstance Shear Stabll' added to bring the grease batch to NLGI#1 grade Com ity and extreme pressure properties are produced whensistency. As can be seen by the data in Table 1, results P coatmg agentsare P y In substantially similar to those of Example 2 are obtained. qi' l li g c l f r l lvely mexpenslve,

co merc a a u EXAMPLE 4.P REPARATION OF ANOTHER fi g f e an mm at .gfi gWITH A further advantage of this invention is that numerous changes,modifications and substitutions can be made In 9 example the Q Coatmgagent 15 added Wlth in the choice of lubricating oils and coating agentswiththe orlgmal charge. The procedure 1s as follows. All of outdgpal'ting f the inventive concept The metes gf fgg i i gl gg z ggiigi zldentlcal to those and bounds of this invention are best gleaned by theA 10.8 parts by weight portion of mineral oil, 22 parts 2:22: whlchfollow read m comuncnon wlth the speclfi. by weight of asbestos and 0.45parts by weight of the W 1 TMHQ polymer employed previously, are chargedto a h h reaction vessel and heated with stirring to 350 F. After greatscomposl Ion avmg Superior s 3 sta 1 holding the batch at thistemperature for 30 minutes, the .water'reslstance and pressurePropertles: batch is quench-cooled to 300 F. by the addition of 1.5prfsmg about 65 to 90 weight PerFent of lubncatmg parts by weight of themineral oil. An additional 4.5 parts i 011 from about 35 to 10 welght Pffi a by weight of mineral oil is added to the batch to bring itthlckenmg System made p of 25 to 9 fivelght Percent t0 NLGI #1 gradeconsistency. An improved yield of of fibrous asbestos and about 10 to 1we1ght percent of grease is obtained, which, as can be seen by the datain Polymeric coating agent having recurrmg umts included Table I, hassatisfactory properties. 40 within the structures:

TABLE I Example 1 2 3 4 iisiiiilil' percent by 3 13, g 14 1 11, 5

oil 85. 7 82% 83.

k I 0 I Test data:

Penetration:

Unworked 224 297 296 286 Worked 00,000 str 355, 312 338 333 Worked100,000 strokes 429 310 361 342 Dro ping point, ASTM D-2265-64T, F 625+625+ 625+ 625+ ShelIroll, ST-230 points change +153 34 11 +22 Waterabsorption, SP-344-60, percent 70 70 70 80 Penetration before 278 278276 265 Penetration emulsion 324 291 282 289 Water washout, 100 F., ASTMD-1264-63% 1.3 3. 5 5.4 6.3 Mean Hertz load 51. 6 59. 3

Bomb oxidation, ASTM D-942-:

100 hr 7 2 5 4 500 hrs s 7 11 10 203 a:.:;;%{;1 492;1,004

350 F., hrs 120; 90 9;

EXAMPLES 5 TO 7.GREASE THICKENED BY R ASBESTOS COATED WITH OTHER TMHQTYPE POLYMERIC QUINOLINES R Using the procedure, equipment, mineral oiland as- R bestos described in Example 2, greases are prepared by 1?replacing the 3 parts of the preferred TMHQ polymer with R n thetrimeric quinoline coating agent described below: Example: Polymericquinoline coating agent wherein n the average degree of polymerizationranges 5 2,2,4-triethyl 1,2-dihydroquinoline from 2 to about 20, and Ris selected from the group 6 2,4-dimethyl-4-ethyl 1,2-dihydroquinolineconsisting of hydrogen, alkyl radicals and hydroxylated 72,2-di-n'propyl 4-methyl 1,2-dihydroquin0- alkyl radicals, said alkylradicals containing from 1 to 6 carbon atoms.

line

2. The grease composition of Claim 1 wherein the lubricating mineral oilis a paraffinic oil.

3. The grease composition of Claim 1 wherein the lubricating mineral oilis a naphthenic oil.

4. The grease composition of Claim 1 wherein the asbestos is colloidalin size.

5. The grease composition of Claim 1 wherein the asbestos isnon-colloidal in size.

6. A grease composition having superior shear stability, waterresistance and extreme pressure properties comprising from about 80 to90 weight percent of mineral oil selected from naphthenic and parafiinicoils having viscosities at 100 F. ranging from 800 SUS to 2000 SUS, fromabout 15 to 9 weight percent of colloidal size chrysotile asbestoscoated with about 5 to 1 weight percent of at least one polymericquinoline coating agent having recurring units included within thestructures:

H LOH: U i/ 1'1 10 wherein n which represents the average degree ofpolymerization ranges from 3 to 6.

7. The grease composition of Claim 6 wherein the polymeric quinolinecoating agent is a trimer.

References Cited UNITED STATES PATENTS DANIEL E. WYMAN, Primary ExaminerI. VAUGHN, Assistant Examiner US. Cl. X.R.

I UNITED STATES PATENT OFFICE v -CERTIFICATE OFCORRECTIQN 1 vi PATENTN0. 3,846,312 I i DATE!) 1 November .5, 1974 INVENTOR(S) 1 Edward A.Cross, Richard L. Frye it is certified that errorappears'in theabove-identified patent and that said Letters Patent are herebycorrected as shown below: I

Column 3,. line 51, for 'l4- l6 sq. meters/gram" insert 45-55 sq.meters/gram Signed and sealed'this ZOthday o'fMay 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON 1 Commissioner of Patents AttestingOfficer and Trademarks

1. A GREASE COMPOSITION HAVING SUPERIOR SHEAR STABILITY,WATER-RESISTANCE AND EXTREME PRESSURE PROPERTIES, COMPRISING FROM ABOUT65 TO 90 WEIGHT PERCENT OF LUBRICATING MINERAL IOL FROM ABOUT 35 TO 10WEIGHT PERCENT OF A THICKENING SYSTEM MADE UP OF 25 TO 9 WEIGHT PERCENTOF FIBROUS ASBESTOS AND ABOUT 10 TO 1 WEIGHT PERCENT OF POLYMERIC COATIGAGENT HAVING RECURRING UNITS INCLUDED WITHIN THE STRUCTURES: